In surgery performed on patients, surgeons generally employ electrosurgical tools to cut tissue and to coagulate bleeding blood vessels in a process known as cautery. An example of a prior art electrosurgical tools is found in U.S. Pat. No. 4,872,454 to DeOliveira et al.
In order to keep the operation site visible, continuous suction devices are used to suction away blood and other debris before they accumulate and to remove smoke that is generated by the electrical cautery process. This suction is vital so that the surgeon's view of the operation site remains unobscured and the operation can proceed safely.
Previously, separate tools were necessary to perform the cautery process and suctioning. If a surgeon uses both tools simultaneously, both hands are occupied which tends to increase the difficulty of the procedure. Use of a separate suctioning device also makes precise positioning of the electrosurgical tool more difficult. To effectively use both devices simultaneously, it is often necessary for an assistant to operate the suction device as the surgeon operates the electrosurgical tool.
To address the foregoing shortcomings of using separate electrosurgical tools and suctioning tools, various combined tools have been developed as disclosed in the following patents:
U.S. Pat. No. 3,494,363 to Jackson
U.S. Pat. No. 4,911,159 to Johnson et al.
U.S. Pat. No. 5,071,418 to Rosenbaum
U.S. Pat. No. 5,318,565 to Kuriloff et al.
U.S. Pat. No. 5,468,240 to Gentelia et al.
The tools disclosed in the above patents use different control schemes for controlling suction while simultaneously operating the cutting and coagulation parts of the tool. In several of the patents, suction must operate continuously as the suction force is also used to control whether the cutting or coagulation function of the tool is selected. This is achieved by the covering or uncovering of various open ports on the body of the tool by the fingers of the user to select a cutting or coagulation mode.
U.S. Pat. No. 5,800,431 to Brown is a prior art tool developed by a co-inventor of the tool of the present invention. The Brown tool has a manually actuatable switch that starts operation of the suction action. When the cutting or coagulation functions are not being used, the suction action is automatically stopped.